The app has only basic options

There should be an easier way to find inbox subfolders

I use at least 13 different categories for my super-complicated schedule, and since the iOS app clips text on calendar events I rely on categories to quickly know which type of event I’m looking at. As it is now, I have to tap on each event to see what it’s about. On the Mac Outlook app, categories work great, and my admin puts in time making sure events are categorized properly. However, I’m usually not in front of my laptop, and so would greatly benefit from seeing categories on the iOS app and the Watch app.

Make it simpler, make it more like iOS mail native client and less Outlook-ish this is mobile platform not PC.

Show all emails instead of just targeted... who’s doing the targeting??

I was in one of the mail folders, (eg. Sent items) and it would be great if mail icon on the bottom sends me back to Inbox while I am already in Mail. It seems it does’t do anything if it’s already in the email mode.

As the title say, when I'm out of work I want to enable do not disturb mode but still get notified when an email marked as important/high priority arrives (for example, a monitoring system alert)

Be like Spark Email for iOS

If you subscribe to a calendar that you add yourself, you can’t turn off reminders!
So I get reminders for all bank holidays which makes no sense.

Please add the ability to turn off reminders for calendars you subscribe to.

I don’t think anyone wants reminders for public holidays and I certainly don’t.

I can’t use the public holiday calendar that you can subscribe to via outlook as it includes N. Ireland, Scotland and Wales holidays which aren’t the same to England so I added an England public holiday calendar which works better, but I don’t want the reminders

Problem:
I had an auth error on one account and while I worked to resolve it, my auth to a different account was reset. I didn't get any notifications about this second account, and clicking through to settings and resetting the account did not trigger the re-auth flow for the second account. I just stopped getting new emails.

Any/all of these Improvements would have helped:
Show popups for each account having auth issues.
Show auth errors when clicking to that account
Trigger re-auth flow if necessary when "Resetting" an account.

Better spam filter please...

Calendar notifications on Mac OS should use native notifications from Mac OS instead of the notifications window.

Notifications window never shows up if you’re in a full screen app and it can get buried under windows, so I end up NEVER EVER seeing it.

Same goes for teams too

Add page number and total pages when viewing attachments such as a PDF in outlook

Incoming phone calls of known contacts are only showing numbers but do not identify contact name